Accuracy of map:

Projection:

Basic contents:

Vector map. Area of species distribution is shown by polygons and sporadic distribution by points. Zones of weediness are shown by polygons.

Accuracy of classifier:

The weed area is subdivided into two zones, one representing species distribution, and the second where weed is considered a serious pest. Points represent locations where sporadic occurrence has been reported. Zone of weediness was allocated according to criteria of occurrence (% of fields where this species is found) and abundance (Tanskii et al., 1998), i.e., where the occurrence of this species exceeded 50% with its field abundance (projective cover) being more than 15%.

Method of map production:

Published literature was reviewed, including Atlases, monographs and papers. Occurrence data were obtained from herbarium specimens, floras, monographs and papers. The X. strumarium area map was compiled based on the weed distribution map for the Far East (Kharkevich, 1992), reference data on the species distribution in floristic regions by Krasnoborov (1997), Krasnoborov (1979), Komarov (1959), as well as the following sources: Blokhin (1982), Burygin & Dzhanguzarov (1975), Galushko (1980), Geideman (1954), Grin.ko et al. (1987), Dokuchaev (1973), Klobukova-Alisova (1960), Kolomiitsev (1999), Kolpikova (1967), Kuminova (1958), Kushnirenko (1949), Ladan (1990), Nikitin & Geldikhanov (1988), Rubtsov (1972), Shablina (1975), Orlova (1997), Prudnikov & Poluyanov (1996), Sal.nikova (1953), Bakin et al. (2000), Stepkin & Rafal.skii (1982), Ul.yanova (1998), Pavlov (1965), Vvedenskii (1965, 1962), Shishkin (1967). Coordinates of habitats were defined and plotted according to the data of Krylov (1949), Tsvelev (2000), Tabaka (1982), Rzhavitin (1968), Shabalina (1975) and Anenkhonov (2001). Herbarium materials from the All-Russian Institute of Plant Protection, Moscow State University, Botanical Institute, and Byelorussian State University were also used. North-western border of the area was drawn along the zone of deciduous forests according to records of the species in Non-Chernozen Zone (Shlyakova, 1982). Its border in Siberia was outlined according to Krasnoborov (1997, 1979) taking into account the map of arable lands (Koroljeva et al., 2003). The southern border of the area was corrected along the borders of deserts and semi-deserts. In Central Asia the area includes only areas with arable lands. The X. strumarium area in the Far East was allocated according to the map of its distribution (Kharkevich, 1992), herbarium materials from the Moscow State University and Botanical Institute, records of the species in Amur Region, Primorskii Territory, and in the south of Khabarovsk Territory according to the following sources: Blokhin (1982), Voroshilov (1966), Kolomiitsev (1999); and taking into account the map of arable lands according to Blokhin (1982), Kolomiitsev (1999), Sal.nikova (1953), Stepkin (1982). Sporadic distribution of the species was determined according to Kharkevich (1992), Tsvelev (2000), Tolmachev (1977) and Anenkhonov (2001). The zone of weediness was allocated according to the literature data and map of arable lands (Koroljeva et al., 2003). Criterion of its allocation was based on the indication of the weed in the literature as the main weed in Stavropol. Territory according to Kolpikova (1967) and Dokuchaev (1973), in Crimea according to Korovina (1981), and Kurgan Region according to Kushnirenko (1949); as a malignant weed in corn and sunflower crops in Krasnodar and Stavropol. Territories (Ul.yanova, 1990); as a weed of grain crops and main weed of young orchards in Donetsk Region (Skorokhod, 1951); as the most widespread weed in Ukraine (Vorob.ev, 1973); as a harmful weed in Rostov (Grin.ko et al., 1987) and Amur Regions (Kolomiitsev, 1999); as the most harmful weed in the Saratov Region (Orlova, 1962); as a dominant weed with high reproduction potential in Georgia (Khubutiya, 1990); having abundance 2-3 points in grain, tobacco and cucumber crops in Azerbaijan (Doronina , 1978); as the most widespread weed having abundance 2-3 points on irrigated lands in Kazakhstan (Zharokova , 1981); having abundance 3 points in Kara-Kalpakstan (Belolipov et al., 1990) and Uzbekistan (Burygin & Dzhanguzarov, 1975); as a weed of vegetable cultures in Kyrgyzstan (Sukhin et al., 1983); having an occurrence of 70% and abundance 2-3 points in Turkmenistan (Nikitin, 1957); as a malignant weed in the center of the Amur Region and in the south of the Khabarovsk Territory (Blokhin, 1982); as a harmful weed in soya crops in the Far East (Stepkin, 1982); as a main weed in the Far East (Sal.nikova & Zakharin, 1953). Data were then compiled through scanning and geo-referencing to develop a composite vector map. The biologist, together with the GIS specialist, drew a composite weed distribution area based on compiled data.